1. Simple solar spectral model for direct and diffuse irradiance on horizontal and tilted planes at the earth's surface for cloudless atmospheres;Bird,1984
2. Terrestrial solar spectral modeling;Bird;Sol. Cells,1983
3. Survey of quantitative data on the solar energy and its spectral distribution;Thekaekara,1975
4. Terrestrial photovoltaic measurement procedures;NASA,1977
5. Air Force Geophysics Laboratory (AFGL), Atmospheric transmittance/radiance codes — LOWTRAN 1 Through 5, (AFGL, Hanscom AFB, MA, U.S.A.).